8-Oxychinolin, 8-OxycMnaldin und 8-OxycMnolin-5-sultons?ure lassen sich

Ohne Zusammenfassung     

Total Synthesis of Several 8, 8",-Biflavones

8,8"-Biflavonoidsareantw0rtantclass0fbiflavonoids.Asasystematicresearchofthe8,8"-biflav0noids,wehavepreviouslyreportedthestudyonthereactionof2'-hydroxychaloneswithl2-H2SO4-DMSOsystem.'InthispaPer,thesynthesisof5,5",7,7',-tetTameth0xy-8,8"-biflavonela2,4,4",7,7"-tetramethoxy-8,8"-biflavone1b',4',4",,5,5,',7,7"-hexamethoxy-8,8"-biflav0ne1c4and4,4"-dibenZyl0xy-5,5",7,7"-tetramothoxy-8,8"-biflavoneldisreported.ThesyntheticmethodisshownintheSchemebelow.2-Hydroxyacet0phenonescondensedwithsubsti…     

8’，8″-去甲基三白脂素-8的全合成

以2-甲氧基酚,丁二酰氯和L-乳酸乙酯为起始原料,用会聚法完成了8’,8”-去甲基三白脂素-8的全合成,总产率1．79％。其结构经1HNMR和MS表征。     

8',8"-去甲基三白脂素-8的全合成

以2-甲氧基酚,丁二酰氯和L-乳酸乙酯为起始原料,用会聚法完成了8',8"-去甲基三白脂素-8的全合成,总产率1.79%.其结构经1H NMR和MS表征.     

Ti8C12H8簇的理论研究

用量子化学从头计算方法, 预测了Ti8C12H8簇的几何结构、电子结构, 分析讨论了该簇的成键和化学反应性质。     

Ce(C_8H_8)_2和Ce(C_8H_8)_2~-的化学键性质

结合改进的重叠模型Xa-SW法和Ziegler过渡态法,通过将中心原子与配体的作用选成离子聚集、中心原子只有s和p轨道参与成键、中心原子只有d轨道参与成键、中心原子只有f轨道参与成键、中心原子的s、p、d和f轨道同时参与成键5种类型,从能量角度分析了Ce(C_8H_8)_2和Ce(C_8H_8)~-_2的化学键性质。     

Synthesis and structure of [Zn8(HPO4)8(H2PO4)8]•[(C2H8N)8]•4H2O

A chain-like zincophosphate [Zn₈(HPO₄)₈(H₂PO₄)₈]•[(C₂H₈N)₈]•4H₂O was obtained at room temperature from a ZnO/P₂O₅/dimethylamine/H₂O mixture. The crystal structure was determined by single crystal X-ray diffraction. The symmetry is monoclinic a=1.26450(7)nm, b=1.08477(5)nm, c=1.46311(4)nm, β=98.793(5)°, space group Cc. The structure consists of chains of zinc-corner-sharing Zn₂P₂O₄ four rings. The negative charge of the chains is compensated by the protonated dimethylamine. The characterization by ³¹P solid state nmr spectroscopy is also reported.     

Aromaticity, optical properties and zero field splitting of homo- and hetero-bimetallic (C8H8)M(μ2-,η8═C8H8)M(C8H8) where M = Ti, Zr, Th Complexes

This work presents a relativistic calculation of electron delocalization, optical properties, and zero field splitting in a group of molecules with the structure (C(8)H(8))M(μ(2)-,η(8)═C(8)H(8))M(C(8)H(8)), where M = Ti, Zr and Th. Additionally we also studied the heterobimetallic combinations (Ti-Th and Zr-Th). The molecular properties are discussed based on their electronic structure and the influence of the electron mobility in metal-metal communication. Nucleus independent chemical shift (NICS) was determined via the gauge-including-atomic-orbital (GIAO) method with the OPBE functional. The time-dependent density functional theory (TDDFT) was employed to calculate excitation energies, and the electronic transitions over 500 nm are presented with the objective to analyze the transition metal role as an antenna effect in the absorption band in the near-IR region. Finally the ZFS was calculated using Pederson-Khana and coupled perturbed DFT approaches implemented in the ORCA code. The contributions to spin-spin coupling (SS) and spin-orbit coupling (SOC) were analyzed, and the spin-density over the metal centers is discussed employing our scheme of metal-metal communication. Our aim is to determine the influence of the electronic structure over the optical and magnetic properties in a group of model compounds to understand the transition metals effect over these properties.     

Resolution of 8′-alkoxy- and hydroxy-1,1′-binaphthalen-8-ols

Enantiopure 8′-ethoxy-, 8′-hydroxy-, and 8′-methoxy-1,1′-binaphthalen-8-ol were readily resolved by separating the corresponding chiral camphanic esters [derived from the esterification of the alcohols with (−)-(1S)-camphanic chloride] based upon their differing solubility in diethyl ether and their differing chromatographic behavior.     

8-葵炔基苯并内酰胺-V8的改良合成

8-葵炔基苯并内酰胺-V8是我们最近发现的具有亚基选择性的PKC调节剂,动物实验表明有抗癌活性。本文探讨了一个对于这个化合物的新的合成路线。以4为原料,通过碘基化反应,成环反应,Pd/CuI催化的葵炔与芳基碘代物的偶联反应等关键步骤,以22.4%的收率得到了该化合物。     

PHOTOCYCLOADDITION BETWEEN 8-METHOXYPSORALEN (8-MOP) AND OLEFINES (Ⅲ)

The photocycloadditions between 8-methoxypsoralen(8-MOP) and olefines have been in-vestigated. It gives a series of head-to-tail cycloadducts. From the reaction rates and cal-culated values of polarizability of olefines it indicates that reaction rates are dependent onthe polarizability of olefines. The stereochemistry of these products has been studied. Inview of these results it shows that the electron-deficient C_3-position of the triplet state of 8-MOP attacks the olefines electro-philically at first, then the reactions proceed to form pro-ducts via diradical mechanism.     

8-epi-Liphagal的合成研究

四环杂萜类天然产物Liphagal含有新奇的[6-7-5-6]四环骨架, 是磷酸肌醇3-激酶(PI3K)的有效抑制剂之一, 可以选择性抑制细胞增殖和促进细胞死亡, 在治疗炎症、免疫紊乱、癌症以及心血管疾病中有潜在的医用价值. 从廉价的2,4,5-三甲氧基苯甲醛出发, 通过Wittig反应、Cu催化的环化反应、选择性氢化、分子内Friedel-Crafts反应, 以直线步骤最长7步, 8.72%的总收率实现了8-epi-Liphagal高级中间体10的合成.     

N8H8环状异构体的结构与稳定性的理论研究

采用密度泛函理论的B3LYP方法在6-311 G**基组水平上对N8H8氮氢环状化合物可能存在的构型进行了几何优化,得到74种稳定异构体,应朋A然键轨道理论NBO和分子中的原子理论AIM分析了这些化合物成键特征和相对稳定性,G3MP2方法汁算了各异构体的能量及生成热.研究结果表明:N原子孤对电子到相邻的氮氮键的超共轭作用是影响氮氮键长变化的丰要因素;N8H8环状异构体的稳定性顺序为:六元环>七元环>八元环,五元环>三元环>四元环,六元环是这些N8H8环状异构体中最稳定的,最不稳定的是四元环,G19是所有环状异构体中能量最低的:M3能量最高,稳定性最差,A7密度最大.